Same reason someone would run rings that were "pre lapped" to a different cylinder than they were to be used in.

I always thought that rings are lapped inside of a cylinder that's the diameter they are made to fit when they are manufactured anyway.

Re: 8.1 inch rod in stock block/stroke 350 and -----

Posted: Sat Oct 21, 2017 5:40 pm

by In-Tech

I thought the whole idea of what DV was doing was to take a block you are going to use, and the pistons/rings you are going to use, and rotate the assembly at a slow speed to "burnish"(for a lesser word), then disassemble/clean, and put the rest of your assembly together after.

To me it seems like a waste of time as I do that with some of my assemblies. Disassemble, clean the bores and brakekleen and blow the pistons and reassemble. In an assembly line DV's method might be a reasonable step. Not knocking it at all, just doesn't seem like a job shop could take advantage of this idea.

Re: 8.1 inch rod in stock block/stroke 350 and -----

I thought the whole idea of what DV was doing was to take a block you are going to use, and the pistons/rings you are going to use, and rotate the assembly at a slow speed to "burnish"(for a lesser word), then disassemble/clean, and put the rest of your assembly together after.

To me it seems like a waste of time as I do that with some of my assemblies. Disassemble, clean the bores and brakekleen and blow the pistons and reassemble. In an assembly line DV's method might be a reasonable step. Not knocking it at all, just doesn't seem like a job shop could take advantage of this idea.

Yes it would seem more feasible if it could be used to prepare the block for the rings as Grumpy and others have done over the years by dynoing the engine and then changing rings for an extra 5 horse but I don't know if that is even necessary with modern day thinner rings.

Re: 8.1 inch rod in stock block/stroke 350 and -----

I thought the whole idea of what DV was doing was to take a block you are going to use, and the pistons/rings you are going to use, and rotate the assembly at a slow speed to "burnish"(for a lesser word), then disassemble/clean, and put the rest of your assembly together after.

To me it seems like a waste of time as I do that with some of my assemblies. Disassemble, clean the bores and brakekleen and blow the pistons and reassemble. In an assembly line DV's method might be a reasonable step. Not knocking it at all, just doesn't seem like a job shop could take advantage of this idea.

I was with ya....until it got to the "blow the pistons" part.......

Re: 8.1 inch rod in stock block/stroke 350 and -----

Posted: Sun Oct 22, 2017 1:24 pm

by In-Tech

Hehe, Mark. The air compressor and the cleaning was not meant to be anywhere close to the girls at sema lmfao

Re: 8.1 inch rod in stock block/stroke 350 and -----

For example the initial turning torque my 383 Chevy short block builds usually runs around 18-20 lbs-ft when done in a conventional fashion. P

This seems high. Are you using a thick ring pack?

The 383's I've done measure about 10 lbs-ft

1/16 -1/16 - 3/16 with finish as per ring manufacturers and it's about what you are getting done my way for a street build. My cup car motor turned at about 6 lbs-ft but it gets difficult to be precise here as I don't have a torque wrench that would read accurately at this low figure.
DV

As a point of interest Mahle has started to offer catalog pistons with 1.0/1.0/3.0 mm rings.An example is the latest Ford/Chevy 4 inch bore stuff.
Turnin g torque on this is measurable lower than 1/16-1/6-3/16th stuff.

As a point of interest Mahle has started to offer catalog pistons with 1.0/1.0/3.0 mm rings.An example is the latest Ford/Chevy 4 inch bore stuff.
Turnin g torque on this is measurable lower than 1/16-1/6-3/16th stuff.

DV

I've used the mahle 1mm 1mm 2mm ring pack shelf pistons on sbcs for a few years now. Very nice setup. I see some others are offering it now.

As a point of interest Mahle has started to offer catalog pistons with 1.0/1.0/3.0 mm rings.An example is the latest Ford/Chevy 4 inch bore stuff.
Turnin g torque on this is measurable lower than 1/16-1/6-3/16th stuff.

DV

The benefits are certainly there, as long as the ring seal and the rings control oil. But I think Mahle being a ring manufacturer is the foundation of that. Some of the companies have a decent factory deal that would seem to allow it, from a cost standpoint, but certainly don't have the flexibility that Mahle has.

A lot of what factories do is fashion and marketing as much as it is technology.

As a point of interest Mahle has started to offer catalog pistons with 1.0/1.0/3.0 mm rings.An example is the latest Ford/Chevy 4 inch bore stuff.
Turnin g torque on this is measurable lower than 1/16-1/6-3/16th stuff.

DV

I've used the mahle 1mm 1mm 2mm ring pack shelf pistons on sbcs for a few years now. Very nice setup. I see some others are offering it now.

I think it's a great idea, but at 190.00 for a set of moly rings it would be a hard sell to most of my customers.....and no sale to theirs. On top of that the steel top ring sets cost more than a set of rods. (that's a joke for those that can't tell)

I'm using 1.5 1.5 3.0 on the 4" bore stuff because the price point is far lower. You don't get the whole benefit, but it's far better than the 1/16 1/16 3.0 .195 radial width stuff, with the radial reduced to .145.

Re: 8.1 inch rod in stock block/stroke 350 and -----

I think it's a great idea, but at 190.00 for a set of moly rings it would be a hard sell to most of my customers.....and no sale to theirs. On top of that the steel top ring sets cost more than a set of rods. (that's a joke for those that can't tell)

I'm using 1.5 1.5 3.0 on the 4" bore stuff because the price point is far lower. You don't get the whole benefit, but it's far better than the 1/16 1/16 3.0 .195 radial width stuff, with the radial reduced to .145.

Ive been getting the mahle rings for around 170 a set in the 1mm size. I didnt think that was bad at all. I'm going to try the CP bullet line this winter in a few motors. 1mm, 1mm, 2mm ring pack, last ported lightweight flat tops for $720 a set with rings. IIRC the mahles were closer to $800.

Re: 8.1 inch rod in stock block/stroke 350 and -----

I think it's a great idea, but at 190.00 for a set of moly rings it would be a hard sell to most of my customers.....and no sale to theirs. On top of that the steel top ring sets cost more than a set of rods. (that's a joke for those that can't tell)

I'm using 1.5 1.5 3.0 on the 4" bore stuff because the price point is far lower. You don't get the whole benefit, but it's far better than the 1/16 1/16 3.0 .195 radial width stuff, with the radial reduced to .145.

Ive been getting the mahle rings for around 170 a set in the 1mm size. I didnt think that was bad at all. I'm going to try the CP bullet line this winter in a few motors. 1mm, 1mm, 2mm ring pack, last ported lightweight flat tops for $720 a set with rings. IIRC the mahles were closer to $800.

Hey - young Sandford that was a red hot post from you for me. I had not looked at CP stuff for a few years now and had lost track of what they were up to lately. Thanks for the speed tip there.

DV

Re: 8.1 inch rod in stock block/stroke 350 and -----

Posted: Sat Oct 28, 2017 2:11 am

by pdq67

I haven't read the complete thread so David, just how are you installing an 8.1" long rod in a 350" SBC engine??

Curious minds want to know!

In the other thread about the big pistons, I have asked how much can the Dart block that will bore to 4.25" be offset bored for max. dia. cylinders"